There are various types of wheelchair on the market, from the simplest manual version to the most sophisticated all-electric version. Faced with the difficulties encountered in daily life, many individuals of reduced mobility are abandoning manual wheelchairs because these wheelchairs require significant physical effort on the part of the users and are not always easy to maneuver, ultimately limiting the independence of the individuals concerned. The latter then have to choose between all of the chairs available on the market, notably according to their disability, their physical capacity and their financial situation.
One solution for allowing these individuals to regain a greater degree of independence is to use an all-electric chair equipped with a control member. Using this control member, the user can activate the chair in all directions, the chair being propelled by means of an electric motor, hand rims coupled to the wheels incidentally still being provided in order to allow manual operation notably if the electric propulsion is unavailable. Another, less expensive, solution is to equip a conventional wheelchair with an additional motorization kit. These motorization kits include kits that electrically assist with propulsion.
Motorization kits that assist with electric propulsion use a sensor on each hand rim to detect the driving movement applied by the user to the hand rim. This sensor may be a simple switch detecting two states, a forward movement and a backward movement. It may also be a switch of the Hall effect type, which measures the position of the hand rim with respect to the wheel, the hand rim having a few degrees of freedom relative to the wheel. The advantage with this type of sensor is that it makes it possible to measure the intensity of the movement applied to the hand rim, this making it possible to apply a propulsion speed that is a function of this intensity. The information delivered by the sensor is transmitted via a rotary commutator to an electronic control board which manages the voltage applied to each wheel motor.
Propulsion assistance may also be commanded by a third party pushing the wheelchair, in order to reduce the pushing effort that the latter has to supply. The command is a device suited to the motor control electronic board or boards.
This solution of electrically assisting propulsion therefore requires sensors on each hand rim, possibly a control member for a third party and means of transmitting the information collected to the control electronics, particularly a rotary commutator on each wheel. The infrastructure required for picking up the instructions commanding propulsion, notably via the hand rim, is therefore complex, bulky and expensive.